Using Document.title To Identify Current Page?

I'm designing a website and I would like to add a certain class to a navigation element based on the document title. I currently have the following javascript. The nav elements have separate ids (the About Us nav element has the id="about" and so on)

<code>
window.onload=function(){
var docTitle = document.title;
var about = document.getElementById("about");
var advising = document.getElementById("advising")

[Code]...

The problem seems to be that the if statement is true whether or not the document.title ="about" or anything else, (if I remove the return, both about us and advising elements have their class changed.